Substituted 7-acetylamino cephalosporanic acids



United States Patent 3,345,368 SUBSTITUTED 7-ACETYLAMINO CEPHALOSPORANIC ACIDS Benjamin Arthur Lewis, Suflern, and Martin Leon Sas- I 3,345,368 Patented Oct. 3, 1967 alkanoyl groups contemplated by the present invention are, for example, 5,8-dithiooctanoyl, 6,8-dithiooctanoyl, 6,8-dithiononanoyl, and the like. Typical 2-alkyl-4,m-dithianealkanoyl groups contemplated by the present invensiver, Pearl River, N.Y., and Robert Gordon Shepherd, 5 :;f :ggfi 2'ethyl'4m-d1- Ridgewood, N.J., assigiors to American Cyanamid y e Company, Stamford Conn a corporation of Maine Also embraced withln the scope of the present inven- No Drawing Filed 15 1957 Sen 1 177 tron are the non-toxic pharmaceutically acceptable salts Claim (Cl. 260-443) I of these derivatives of 7-aminocephalosporan1c ac d. The

10 cations comprised in these salts and embraced by M include, for example, the non-toxic metal cations such as the ABSTRACT OF THE DISCLOSURE sodium ion, potassium ion, calcium ion, magnesium ion as Well as the organic amine cations, such as the tri(lower This disclosure describes compounds of the class of alkynamine cations (6g triethylamine) procaine and 7- [bis-(alkylthio)alkanoylamino]cephalosporanic acids, the like 7'(dithioalkzinoylamino)cephaiosporanic acids i The novel compounds of the present invention, when A gg ggg g igfgfz gg s aclds; is acetoxy in Formulae (I), (II) and (III) above, may be g readily prepared by acylating 7-aminocephalosporanic acid with a compound which may be represented by the f 11 l Brief summary of the invention 9 owing general formu ae This invention relates to new derivatives of 7-arnino- 0 cephalosporanic acid and, more particularly, is concerned R with novel compounds which may be represented by the PS (0132) E (0112) O 2 following general formulae:

0 R1 (IV) $g CH-CHNH (OHz)n(H(CH2)m-S-Rn ACHzC N-..o=o s I H-(OHzh-OH-(CHz) X-( J11- om),,o-z

(302M (1 S (V) s 0 I l (3H1 O11-?H-NH-C-(CHzh-(EEP-(OHQX$H(CH2) H AOHa-C NC=O (i1 COzM (II) s 0 0 lg a (i711: OHCHNH- (CH2)n CHCHQOH(CHZ)Y H-(OHz) -OH-OHz-CH-(CHQr- -Z A-OHz-C N- =0 S-CH-S -CH (I) R I v R (VI) (301M (III) wherein R, R R n, m, at and y are as hereinbefore wherein R is lower alkyl, R and R2 are lower alkyl or phenyl lower alkyl, n is 3 or 4, m is 2 or 3, x is 1 or 2,

y is O or 1, A is acetoxy or N-primidinium'and M is hydrogen, pharmaceutically acceptable non-toxic cations or an anionic charge When A is N-pyridinium. Suitable lower alkyl groups are those having from 1 to 4 carbon atoms such as methyl, ethyl, isopropyl, n-butyl, etc. Suitable phenyl lower alkyl groups are, for example, benzyl, a

B-phenylethyl, qz-phenylethyl, and the like.

Detailed description of the invention In the general Formulae (I), (II) and (III) set forth above, in those instances Where A is N-pyridinium, the

defined and Z is a halide (preferably chloride), azide, acyloxy or p-nitrophenoxy group. This acylation of the 7-aminocephalosporanic acid is performed, for example, by the Schotten-Baumann method, taking into consideration the sensitivity of these compounds, under mild conditions and advantageously in the presence of a diluent orsolvent such as water or an organic solvent, for example, a ketone such as acetone, an ether such as tetrahydrofuran, or a halogenated hydrocarbon such as chloroforrn or methylene chloride. The reaction is preferably conducted in the presence of a basic agent such as sodium bicarbonate or potassium bicarbonate, or an organic base such as one of the organic bases listed hereinbefore. The reaction is also preferably carried out at a temperature of from about 0C. to about 25 0., preferably at 0 C.5' C.; andover a period of time of a few hours or more. 7 The acylating agents corresponding to the Formulae I (IV), (V) and (VI), when new, may be prepared by methods well-known in the art from the corresponding acids (Z is hydroxy). Thus, the acid can be treated with thionyl chloride or oxalyl chloride, if desired in the presonce of dimethylformamide, to yield the corresponding acyl chlorides (Z is chlorine), which, if desired, can be converted to the acyl azides (Z is N by treatment with sodium vazide. The p-nitrophenyl esters (Z is p-nitrophenoxy) can be prepared by following the procedure of Bodanszky et al. (Biochemical Preparations, vol. 9, p. 110, 1962, John Wiley and Sons, New York, N. Y.). Specific acylating agents operable in this process include, for example, 6,8-bis-(methylthio)octanoyl chloride, 6- methylthio-8-ethylthiooctanoyl bromide, 5,8-bis-(ethylthio)octanoyl azide, p-nitrophenyl 6,9-bis-(isopropylthio) nonanoate, 6,8-bis-(benzylthio)octanoyl bromide, pnitrophenyl 5,8-dithiooctanoate, 6,8-dithiooctanoyl azide, 6,8-dithiononanoyl bromide, 2-methyl-4,m-dithianepentanoyl chloride, 2-ethyl-4,m-dithianebutanoyl chloride, and the like.

The novel compounds of the present invention, when A is N-pyridinium in Formulae (I), (II) and (III) above, may be readily prepared from the corresponding 7-aminocephalosporanic acid derivatives (A is acetoxy in Formulae (I), (II) and (III) above) by treatment with pyridine in water or aqueous acetone at 20-50 C. and for a period of time of about 1-3 days. The resulting 3- (l-pyridylmethyl)-3-cephem-4-carboxylic acid betaines may then be isolated by standard procedures of precipitation and crystallization.

Depending on the reaction condition used, the new compounds of the present invention are obtained in the free form or in the form of their salts. From the salts it is possible to prepare the acids in known manner, or from the acids the salts are readily accessible, for example, by reaction with hydroxides, carbonates or bicarbonates of alkali metals or alkaline earth metals, or with organic amines.

The novel compounds of the present invention are biologically active and have been found to possess antibacterial activity. As indicated, they are useful antimicrobial agents and have high antimicrobial activity in vitro against standard laboratory microorganism used to screen for activity against pathogens. The antibacterial spectrum of typical compounds of the present invention, representing the concentration required to inhibit the growth of various typical bacteria, was determined in a standard manner by the agar-dilution streak-plate technique which is commonly used in testing new antibiotics. The following table summarizes the in vitro activity of 7 [6,8-bis-(methylthio)octanoylamino]cephalosporanic acid 1), 7- 5,'8-dithiooctanoylamino cephalosporanic acid (2), 7- 6,8-dithiooctanoylamino cephalosporanic acid (3 7- 6,8-di-thiononanoylamino) cephalosporanic acid (4), 7 (2 methyl 4,m-dithianepentanoylamino) cephalosporanic acid (5) and 7-[6,8-bis-(benzylthio)- octanoylamino]cephalosporanic acid (-6) as compared with Cephalosporin C -(7) against a variety of diseasecausing microorganisms.

The compounds of the present invention retained antibacterial activity after exposure to cephalosporinase, a bacterial enzyme, which completely destroyed the activity of Cephalosporin C under the same conditions.

The high in vitro antibacterial activity of the novel compounds of the present invention makes them useful as, additives to materials which are subject to microbial deterioration such as cutting oils and fuel oils. They are also useful in soaps, shampoos and topical compositions for the treatment of wounds and burns.

The invention wil be described in greater detail in conjunction with the following specific examples.

EXAMPLE 1 Preparation of 7-[6,8-bis-(methylthio)octanoylamino1cephalosporanic acid 6,8-bis-(methylthio)octanoic acid (472 .mg., 2 mmole) is converted to its acid chloride with oxalyl chloride. The acid chloride in acetone (20 ml.) is added to a stirred solution of 7-aminocephalosporanic acid (545 mg., 2 mmole) and sodium bicarbonate 504 mg., 6 mmole) in Water (40 ml.) and acetone (20 ml.) which is kept between 0" C. and 5 C. The reaction is stirred for 2 hours at this temperature, and then the acetone is removed under reduced pressure. The aqueous solution is acidified to pH 1 with hydrochloric acid and the mixture extracted with ethyl acetate (3 X 50 ml.) the ethyl acetate solution is washed with water ml.) and dried over magnesium sulfate. Evaporation of the solvent under reduced pressure gives 7-[6,8-bis-(methylthio)octan0ylamino1cephalosporanic acid. The sodium salt is obtained by slurrying this product in water '(10 ml.) and adding 2 N sodium hydroxide dropwise to pH 5 to effect solution. The solution is concentrated to a small volume in a rotary evaporator at 50 C., and the sodium salt is precipitated by the addition of acetone. The precipitate is collected by filtration and dried to give 360 mg. of sodium 7 [6,8 bis-(methylthio)octanoylamino]cephalosporanate as an ivory solid.

EXAMPLE 2 Preparation of 7-[6,8-bis-'(ethylthio) octanoylamino1cephalosporanic acid By replacing the 6,-8-bis-(methylthio)octanoyl chloride employed in Example 4 with an equimolec'ular quantity of 6,8-bis-(ethylthio)octanoyl bromide and following substantially the same procedure described in Example 1, there is obtained the 7-[6,8-bis-(ethylthio)octanoylamino1cephalosporanic acid in equally good yield.

EXAMPLE 3 Preparation of [7-6,8-bis-(benzylthio)octanoylamin01cephalosporanic acid Preparation of 7- (5,8-dithiooctan0ylamino)- cephalosporanic acid In place of the 6,8-bis-(methylthio)octanoyl chloride of Example 1, there is employed an equimolecular quantity of p-nitrophenyl 5, 8-dithiooctanoate whereby the 7 (5,8-dithiooctanoylamino)cephalosporanic acid is obtained in equally good yield.

EXAMPLE 5 Preparation of 7-(6,8-dithiooctan0ylamin0)- cephalosporanic acid In the manner described in Example 1, treatment of 7-aminocephalosporanic acid with -6, 8-dithiooctanoyl chloride produce the 7-(6,S-dithiooctanoylamino)cephalosporanic acid.

EXAMPLE 6 Preparation of 7-[6,8-bis-(methylthio)octalnoylamino]- 3-(1-pyridylmethyl) -3-cephem-4-carboxylic acid betaine One gram of the sodium salt of 7-[6,8-bis-'(methylthio)-octanoylamino]cephalosporanic acid and 8 ml. of pyridine was dissolved in '50 ml. of water, which was ad- 6 justed to pH 6 with acetic acid, and stored under nitrowherein R is lower alkyl, R and R are each selected gen for 3 days at 37 C. The solution was evaporated to from the group consisting of lower alkyl and phenyl dryness and the residue was triturated with acetone to lower alkyl, n has a value selected from the group congive the product. sisting of 3 and 4, in has a value selected from the group EXAMPLE 7 5 consisting of 2 and 3, x has a value selected from the group consisting of 1 and 2, y has a value selected from the group consisting of 0 and l, A -is selected from the group consisting of acetoxy and N-pyridinium and 'M is one gram of the f Salt of Q Y selected from the group consisting of hydrogen, pharamino)cephalosporan1c acid and 8 ml. of pyridine was 10 maceutically acceptable non-toxic cations and an anionic dissolved in 50 ml. of water, which was ad usted to pH charge when A is N pyridinium Preparation of 7-(6,8-dithi00ctanoylamin0)-3-(1-pyriaylmethyl) -3-cephem-4-cwrbovcylic acid betaine 6 with acetic acid, and stored under nitrogen for 3 days 2 A compound according to claim 1, Formula (I), fi il i' a 1225 22 3; i :5; zgi gi i s gf a wherein R and R are methyl, n is 4, m is 2, A is acetoxy g1 e 6 pro and M is hydrogen. EXAMPLE 8 3. A compound according to claim 1, Formula (I),

wherein R and R are methyl, n is 4, m is 2, A is N- Preparwtion of 7-(2-methyl-4,m-ttith ir nepentawoylpyridinium and M is an anionic charge amino)cephalosporanw 4. A compound according to claim 1, Formula (I),

In the manner described in Example 1, treatment of wherein R and R are ethyl, n is 4, m is 2, A is acetoxy 7-aminocephalosp0ranic acid with 2-methyl-4,mdithianeand M is hydrogen.

pentanoyl chloride produces the 7-(2-r nethyl-4,m-di- 5. A compoundv according to claim 1, Formula (I), thianepentanoylamino)-cephalosporan1c acid in equally wherein R1 and R2 are benzyl, n i 4 m i 2 A is acetoxy good Y l V and M is hydrogen.

What 15 clalmed 1S: 6. A compound according to claim 1, Formula (II), 1. A compound selected from the group consisting of wherein n i 3, x i 2, y is O, A is acetoxy and M is bythose of the formulae: drogen.

7. A compound according to claim 1, Formula (II), 011, 0H o1-1-Nr1 c 0 0 cH, s wherein n is 4, x is 1, y is 0, A is acetoxy and M is hy- A-OH c: I I-( )O s dmgen' 2- 8. A compound according to claim 1, Formula (II), R1 wherein n is 4, x is 1, y is 0, A is 'N-pyrid-inium and M 002M is an anionic charge.

s 0 H 311, CH-CH-NH-C-(CHz)n(i7H(CHz)xfiJH( 2)v A-CHa-C NO=O s-s o (302M (II) 9. A compound according to claim 1, Formula (III), wherein R is methyl, n is 4, y is '0, A is acetoxy and M is S 0 hydrogen. 1| 10. A compound according to claim 1, Formula (III), (I332 EY (CH)CH CHTCH'(CH2)Y H wherein R is methyl, n is 4, y is 0, A is N-pyridinium and A-CHPO NC=O s-on-s M is an anionic charge.

| No references cited. 0 0 2M (III) NICHOLAS S. RIZZO, Primary Examiner. 

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF THOSE OF THE FORMULAE: 